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From: Weiyi Lu <weiyi.lu@mediatek.com>
To: Nicolas Boichat <drinkcat@chromium.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Stephen Boyd <sboyd@codeaurora.org>,
	Rob Herring <robh@kernel.org>
Cc: James Liao <jamesjj.liao@mediatek.com>,
	Fan Chen <fan.chen@mediatek.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-mediatek@lists.infradead.org>, <linux-clk@vger.kernel.org>,
	<srv_heupstream@mediatek.com>, <stable@vger.kernel.org>,
	Weiyi Lu <weiyi.lu@mediatek.com>
Subject: [PATCH v3 12/12] clk: mediatek: Allow changing PLL rate when it is off
Date: Mon, 10 Dec 2018 15:32:40 +0800
Message-ID: <20181210073240.32278-14-weiyi.lu@mediatek.com> (raw)
In-Reply-To: <20181210073240.32278-1-weiyi.lu@mediatek.com>

From: James Liao <jamesjj.liao@mediatek.com>

Some modules may need to change its clock rate before turn on it.
So changing PLL's rate when it is off should be allowed.
This patch removes PLL enabled check before set rate, so that
PLLs can set new frequency even if they are off.

On MT8173 for example, ARMPLL's enable bit can be controlled by
other HW. That means ARMPLL may be turned on even if we (CPU / SW)
set ARMPLL's enable bit as 0. In this case, SW may want and can
still change ARMPLL's rate by changing its pcw and postdiv settings.
But without this patch, new pcw setting will not be applied because
its enable bit is 0.

(am from https://patchwork.kernel.org/patch/9411983/)

Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Acked-by: Michael Turquette <mturuqette@baylibre.com>
Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
---
 drivers/clk/mediatek/clk-pll.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
index 81400601f107..03b20e3bca4e 100644
--- a/drivers/clk/mediatek/clk-pll.c
+++ b/drivers/clk/mediatek/clk-pll.c
@@ -96,13 +96,10 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
 		int postdiv)
 {
 	u32 con1, val;
-	int pll_en;
 	u32 tuner_en = 0;
 	u32 tuner_en_mask;
 	void __iomem *tuner_en_addr = NULL;
 
-	pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN;
-
 	/* disable tuner */
 	if (pll->tuner_en_addr) {
 		tuner_en_addr = pll->tuner_en_addr;
@@ -141,8 +138,7 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
 
 	con1 = readl(pll->base_addr + REG_CON1);
 
-	if (pll_en)
-		con1 |= CON1_PCW_CHG;
+	con1 |= CON1_PCW_CHG;
 
 	writel(con1, pll->base_addr + REG_CON1);
 	if (pll->tuner_addr)
@@ -155,8 +151,7 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
 		writel(val, tuner_en_addr);
 	}
 
-	if (pll_en)
-		udelay(20);
+	udelay(20);
 }
 
 /*
-- 
2.18.0


  parent reply index

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-10  7:32 [PATCH v3 00/11] Mediatek MT8183 clock and scpsys support Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 00/12] " Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 01/12] clk: mediatek: fixup: Disable tuner_en before change PLL rate Weiyi Lu
2018-12-14 21:57   ` Stephen Boyd
2019-02-01  8:21     ` Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 02/12] clk: mediatek: add new clkmux register API Weiyi Lu
2018-12-10 12:30   ` Nicolas Boichat
2019-02-01  8:22     ` Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 03/12] clk: mediatek: add configurable pcwibits and fmin to mtk_pll_data Weiyi Lu
2018-12-14 22:02   ` Stephen Boyd
2019-02-01  8:22     ` Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 04/12] soc: mediatek: add new flow for mtcmos power Weiyi Lu
2018-12-10 12:52   ` Nicolas Boichat
2018-12-10  7:32 ` [PATCH v3 05/12] dt-bindings: ARM: Mediatek: Document bindings for MT8183 Weiyi Lu
2018-12-14 21:57   ` Stephen Boyd
2018-12-10  7:32 ` [PATCH v3 06/12] clk: mediatek: Add dt-bindings for MT8183 clocks Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 07/12] clk: mediatek: Add flags support for mtk_gate data Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 08/12] clk: mediatek: Add MT8183 clock support Weiyi Lu
2018-12-11  1:00   ` Nicolas Boichat
2019-02-01  8:22     ` Weiyi Lu
2018-12-14 21:59   ` Stephen Boyd
2019-02-01  8:22     ` Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 09/12] dt-bindings: soc: fix typo of MT8173 power dt-bindings Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 10/12] dt-bindings: soc: Add MT8183 " Weiyi Lu
2018-12-10  7:32 ` [PATCH v3 11/12] soc: mediatek: Add MT8183 scpsys support Weiyi Lu
2018-12-10  7:32 ` Weiyi Lu [this message]
2018-12-14 22:01   ` [PATCH v3 12/12] clk: mediatek: Allow changing PLL rate when it is off Stephen Boyd
2019-02-01  8:22     ` Weiyi Lu

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